La rotation UIImage en Swift

Ici est une simple extension de UIImage:

//ImageRotation.swift

import UIKit
extension UIImage {  
public func imageRotatedByDegrees(degrees: CGFloat, flip: Bool) -> UIImage {
let radiansToDegrees: (CGFloat) -> CGFloat = {
return $0 * (180.0 / CGFloat(M_PI))
}
let degreesToRadians: (CGFloat) -> CGFloat = {
return $0 / 180.0 * CGFloat(M_PI)
}
//calculate the size of the rotated view's containing box for our drawing space
        let rotatedViewBox = UIView(frame: CGRect(origin: CGPointZero, size: size))
let t = CGAffineTransformMakeRotation(degreesToRadians(degrees));
rotatedViewBox.transform = t
let rotatedSize = rotatedViewBox.frame.size
//Create the bitmap context
        UIGraphicsBeginImageContext(rotatedSize)
let bitmap = UIGraphicsGetCurrentContext()
//Move the origin to the middle of the image so we will rotate and scale around the center.
        CGContextTranslateCTM(bitmap, rotatedSize.width / 2.0, rotatedSize.height / 2.0);
//  //Rotate the image context
        CGContextRotateCTM(bitmap, degreesToRadians(degrees));
//Now, draw the rotated/scaled image into the context
        var yFlip: CGFloat
if(flip){
yFlip = CGFloat(-1.0)
} else {
yFlip = CGFloat(1.0)
}
CGContextScaleCTM(bitmap, yFlip, -1.0)
CGContextDrawImage(bitmap, CGRectMake(-size.width / 2, -size.height / 2, size.width, size.height), CGImage)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}
}

(Source)

L'utiliser avec:

rotatedPhoto = rotatedPhoto?.imageRotatedByDegrees(90, flip: false) 

La première rotation d'une image et de le retourner si flip est définie sur true.

extension UIImage {
struct RotationOptions: OptionSet {
let rawValue: Int
static let flipOnVerticalAxis = RotationOptions(rawValue: 1)
static let flipOnHorizontalAxis = RotationOptions(rawValue: 2)
}
func rotated(by rotationAngle: Measurement<UnitAngle>, options: RotationOptions = []) -> UIImage? {
guard let cgImage = self.cgImage else { return nil }
let rotationInRadians = CGFloat(rotationAngle.converted(to: .radians).value)
let transform = CGAffineTransform(rotationAngle: rotationInRadians)
var rect = CGRect(origin: .zero, size: self.size).applying(transform)
rect.origin = .zero
let renderer = UIGraphicsImageRenderer(size: rect.size)
return renderer.image { renderContext in
renderContext.cgContext.translateBy(x: rect.midX, y: rect.midY)
renderContext.cgContext.rotate(by: rotationInRadians)
let x = options.contains(.flipOnVerticalAxis) ? -1.0 : 1.0
let y = options.contains(.flipOnHorizontalAxis) ? 1.0 : -1.0
renderContext.cgContext.scaleBy(x: CGFloat(x), y: CGFloat(y))
let drawRect = CGRect(origin: CGPoint(x: -self.size.width/2, y: -self.size.height/2), size: self.size)
renderContext.cgContext.draw(cgImage, in: drawRect)
}
}
}

Vous pouvez l'utiliser comme ceci:

let rotatedImage = UIImage(named: "my_amazing_image")?.rotated(by: Measurement(value: 48.0, unit: .degrees))

Avec retournée indicateur spécifique:

let flippedImage = UIImage(named: "my_amazing_image")?.rotated(by: Measurement(value: 48.0, unit: .degrees), options: [.flipOnVerticalAxis])

Swift 3:

Rotation à droite:

let image = UIImage(cgImage: otherImage.cgImage!, scale: CGFloat(1.0), orientation: .right)

Testé dans l'aire de Jeux:

//MyPlayground.playground

import UIKit
import PlaygroundSupport
let view = UIView(frame: CGRect(x: 0, y: 0, width: 500, height: 500))
view.backgroundColor = UIColor.white
PlaygroundPage.current.liveView = view
let otherImage = UIImage(named: "burger.png", in: Bundle.main,
compatibleWith: nil)
let imageViewLeft = UIImageView(image: UIImage(cgImage: (otherImage?.cgImage!)!, scale: CGFloat(1.0), orientation: .left)) 
let imageViewRight = UIImageView(image: UIImage(cgImage: (otherImage?.cgImage!)!, scale: CGFloat(1.0), orientation: .right))
view.addSubview(imageViewLeft)
view.addSubview(imageViewRight)
view.layoutIfNeeded()

@confile réponse mis à jour à Swift 4

import UIKit
extension UIImage {
public func imageRotatedByDegrees(degrees: CGFloat, flip: Bool) -> UIImage {
let radiansToDegrees: (CGFloat) -> CGFloat = {
return $0 * (180.0 / CGFloat.pi)
}
let degreesToRadians: (CGFloat) -> CGFloat = {
return $0 / 180.0 * CGFloat.pi
}
//calculate the size of the rotated view's containing box for our drawing space
        let rotatedViewBox = UIView(frame: CGRect(origin: .zero, size: size))
let t = CGAffineTransform(rotationAngle: degreesToRadians(degrees));
rotatedViewBox.transform = t
let rotatedSize = rotatedViewBox.frame.size
//Create the bitmap context
        UIGraphicsBeginImageContext(rotatedSize)
let bitmap = UIGraphicsGetCurrentContext()
//Move the origin to the middle of the image so we will rotate and scale around the center.
        bitmap?.translateBy(x: rotatedSize.width / 2.0, y: rotatedSize.height / 2.0)
//  //Rotate the image context
        bitmap?.rotate(by: degreesToRadians(degrees))
//Now, draw the rotated/scaled image into the context
        var yFlip: CGFloat
if(flip){
yFlip = CGFloat(-1.0)
} else {
yFlip = CGFloat(1.0)
}
bitmap?.scaleBy(x: yFlip, y: -1.0)
let rect = CGRect(x: -size.width / 2, y: -size.height / 2, width: size.width, height: size.height)
bitmap?.draw(cgImage!, in: rect)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage!
}
}

Pour Swift 4.2

extension UIImage {
func rotate(_ radians: CGFloat) -> UIImage {
let cgImage = self.cgImage!
let LARGEST_SIZE = CGFloat(max(self.size.width, self.size.height))
let context = CGContext.init(data: nil, width:Int(LARGEST_SIZE), height:Int(LARGEST_SIZE), bitsPerComponent: cgImage.bitsPerComponent, bytesPerRow: 0, space: cgImage.colorSpace!, bitmapInfo: cgImage.bitmapInfo.rawValue)!
var drawRect = CGRect.zero
drawRect.size = self.size
let drawOrigin = CGPoint(x: (LARGEST_SIZE - self.size.width) * 0.5,y: (LARGEST_SIZE - self.size.height) * 0.5)
drawRect.origin = drawOrigin
var tf = CGAffineTransform.identity
tf = tf.translatedBy(x: LARGEST_SIZE * 0.5, y: LARGEST_SIZE * 0.5)
tf = tf.rotated(by: CGFloat(radians))
tf = tf.translatedBy(x: LARGEST_SIZE * -0.5, y: LARGEST_SIZE * -0.5)
context.concatenate(tf)
context.draw(cgImage, in: drawRect)
var rotatedImage = context.makeImage()!
drawRect = drawRect.applying(tf)
rotatedImage = rotatedImage.cropping(to: drawRect)!
let resultImage = UIImage(cgImage: rotatedImage)
return resultImage
}
}

Vérifier:

func rotatedImage(with angle: CGFloat) -> UIImage {
let updatedSize = CGRect(origin: .zero, size: size)
.applying(CGAffineTransform(rotationAngle: angle))
.size
return UIGraphicsImageRenderer(size: updatedSize)
.image { _ in
let context = UIGraphicsGetCurrentContext()
context?.translateBy(x: updatedSize.width / 2.0, y: updatedSize.height / 2.0)
context?.rotate(by: angle)
draw(in: CGRect(x: -size.width / 2.0, y: -size.height / 2.0, width: size.width, height: size.height))
}
.withRenderingMode(renderingMode)
}